Jodie is a canine with special powers, scientists have discovered. The golden labrador can smell and identify particular bacteria and could soon play a key role in helping researchers develop a programme in which dogs could sniff out individuals infected with dangerous microbes.
The project, recently launched by scientists at Imperial College London, could be vital in the battle against antibiotic resistance as well as the treatment of patients with lung disease and other conditions, they say.
“We believe Jodie and her fellow medical detective dogs point to a new way to spot infected individuals, just by having a sniff of their socks or shirts,” said Professor Jane Davies at Imperial College.
“They could become a major help in tackling antimicrobial resistance and conditions like cystic fibrosis.”
Cystic fibrosis is one of the world’s most common inherited illnesses. A defective protein allows mucus to build up in lungs and other organs, triggering chronic infections that worsen through life.
Eighty years ago, most patients died in their teens. However drugs, called modulators, now offer patients a chance to live into old age. But this success has brought problems.
Modulator drugs have greatly improved patients’ overall conditions but they do not entirely kill off all the chronic lung infections that affect them. Most are still infected with bacteria whose growth could jeopardise their health.
“The problem is that bacteria in these patients are now much harder to detect,” said Davies. “Modulators greatly reduce the mucus in their lungs and without that it is difficult for them to cough up the sputum in which their bacterial status can be evaluated.” “This is where the dogs come in.”
Several years go, Davies and her team, supported by the Cystic Fibrosis Trust, carried out research in which dogs demonstrated they could detect samples grown in the laboratory which contained a bacterium called pseudomonas, which can trigger pneumonia, urinary tract infections and septicaemia – often a serious health problem for cystic fibrosis patients.
As part of the trials, dogs, which were provided by the charity Medical Detection Dogs and which included Jodie, were brought into a testing room where samples were set on stands at dog-head height. These stands either included pseudomonas, other bacteria or no bacteria at all.
The dogs walked around the room sniffing each sample and when they had detected the pseudomonas, they sat down.
“We showed that in laboratory settings dogs can detect pseudomonas in samples,” said Davies. “Now we want to expand that work and have just been given funding from the medical charities LifeArc and the Cystic Fibrosis Trust to ramp up our collaboration with Medical Detection Dogs so that, for the first time, we may be able to train dogs to detect pseudomonas on patients’ skin, in their urine or in their clothing.”
Crucially, this system could be expanded to detect bacteria in other patients, not just those with cystic fibrosis. And such an ability would have important implications.
Microbes such as pseudomonas are difficult to detect in clinics and techniques to test for it are often invasive, uncomfortable, expensive and cannot be repeated on a regular basis. Dogs could get around that problem.
“Bacteria like pseudomonas are often resistant to certain antibiotics,” added Davies. “We need to pinpoint them with precision to ensure they are treated with the right antibiotic and so keep down the growing problem of antimicrobial resistance, which will be worsened if we give patients the wrong type of antibiotics.”
About a million people now die every year across the world because of the spread of microbial resistance and that figure is expected to rise over the next 25 years.
Recent data suggests problems arising from resistance are easing for the under-fives, but for the over-70s mortality rates have gone up 80% since 1990.
“In the fight against antimicrobial resistance, we are going to need all the help we can get – and dogs like Jodie could be the perfect allies that we could recruit in this battle,” said Davies.
